THE British Prime Minister Boris Johnson and his partner Carrie Symonds are now formally engaged with Carrie pregnant.

“The prime minister and Miss Symonds are very pleased to announce their engagement and that they are expecting a baby in the early summer,” a spokesperson for the couple announced yesterday.

Johnson, 55, already has four grown-up children with his second wife Marina Wheeler.

They were married 25 years ago but are now separated and have reached a financial settlement.

The last child born to a sitting prime minister belonged to David and Samantha Cameron, who welcomed Florence Rose Endellion into their family in August 2010.